Mobile station, radio telecommunication system and methods for operating radio telecommunications systems

ABSTRACT

The invention provides methods and apparatus, including mobile stations to enable the mobile station to encode and/or decode messages, for example messages broadcast by the base station on a broadcast channel. The encoding and decoding is based on a set of rules downloaded to the mobile station into an area of application space or storage dedicated to this function.

TECHNICAL FIELD

The present invention relates to the field of telecommunication systemsand is particularly, but not exclusively, applicable to the inventionrelates to mobile radio communication systems, such as those envisagedin the GSM (Global System for Mobile communications) or UMTS (UniversalMobile Telecommunications Standard).

BACKGROUND

Mobile or portable cellular telephones are typically arranged tocommunicate via a radio link to a base station of a network.Alternatively, a mobile telephone may communicate directly with asatellite.

Increasingly, cellular radio communications technology is being builtinto other devices. These include portable laptop ‘or notebook’computers and ‘personal digital assistants’. These devices can then alsosend data or voice over cellular communications networks.

In future, practically any device may be able to communicate over acellular communications network.

An analogous form of technology to the cellular telephone consists ofdigital portable and mobile radios with private networks. These arecommonly referred to as ‘PMR’ radios. Portable and mobile radios may bearranged either to communicate with one another via base stations, ordirectly with one another in ‘direct mode’. The communication willtypically either be over a digital simplex communication channel, orover a digital semi-duplex communication channel.

Mobile communications devices are commonly referred to as ‘mobilestations’. In the following, the term mobile station will be used todescribe any such electronic device capable of transmission andreception of voice and/or data including cellular transceivers (bothterrestrial and satellite) and radio pagers.

The next generation of mobile stations will operate in accordance with astandard referred to as the universal mobile telephone standard (UMTS).The UMTS infrastructure will offer varying levels of service for UMTSmobile stations.

One goal of UMTS is the efficient use of the bandwidth associated withthe Imited radio spectrum available to system operators. Another goal isthe orderly function of a variety of different levels of service offeredby the network. A further goal is supporting a wide variety of UMTSmobile stations with varying capabilities. For example, whilst a UMTScell might offer the possibility for a mobile station to transmit videoimagery, many mobile stations operating within that cell may not becapable of transmitting or receiving video imagery.

In cellular telecommunication systems, such as GSM and UMTS, the 25broadcast capacity is limited for a number of different reasons. In thecase of GSM, the original system design makes it difficult to extend thecontrol channel overheads specified with the existing standard. Thebroadcast channels use spectrum for non-chargeable purposes. This may beseen as undesirable by an operator. The problem of broadcast capacity isa particular problem for multi-mode systems, in which there is a need tobroadcast information about several modes, thus utilising significantamounts of the bandwidth allocation.

SUMMARY OF THE INVENTION

The above object is met by the combinations of features of the mainclaims, and the dependent claims disclose further advantageousembodiments of the invention.

According to a first aspect of the invention there is provided a mobilestation for communicating with a radio telecommunications system, themobile station comprising:

-   -   means for communicating with the radio telecommunications        system;    -   means for storing rule information relating to predetermined        coding rules;    -   means for retrieving said rule information;    -   means for decoding, using the retrieved rue information, signals        received from the radio telecommunications system.

According to a second aspect of the invention there is provided a mobilestation for communication over a telecommunications system, the mobilestation comprising:

-   -   means for communicating with the radio telecommunications        system: means for storing and retrieving rule information        relating to predetermined coding rules:    -   means for encoding, using the retrieved rule information,        signals to be transmitted to the radio telecommunications system

According to a third aspect of the invention there is provided a firstmobile station for communicating with second mobile station in atelecommunications system, the first mobile station comprising:

-   -   means for storing rule information relating to predetermined        coding rules;    -   means for communicating with the second mobile station;    -   means for retrieving said rule information:    -   means for encoding or decoding, using the retrieved rule        information, signals to be transmitted to or signals received        from the second mobile station, which signals use the        predetermined coding rules.

According to a fourth aspect of the invention there is provided a radiotelecommunications system comprising:

-   -   at least one base station;    -   at least one mobile station;    -   the at least one base station including means for transmitting        signals to and means for receiving signals from the at least one        mobile station;    -   the at least one mobile station including means for receiving        signals from and means for transmitting signals to the at least        one base station;    -   the mobile station including means for storing rule information        relating to predetermined coding rules;    -   the mobile station also including means for retrieving said rule        information; and    -   the mobile station further including means for decoding, using        the retrieved rule information, signals transmitted by the base        station using the predetermined coding rules.

According to a fifth aspect of the invention there is provided a radiotelecommunications system comprising:

-   -   at least one base station;    -   at least one mobile station;    -   the at least one base station including means for transmitting        signals to and means for receiving signals from the at least one        mobile station;    -   the at least one mobile station including means for receiving        signals from and means for transmitting signals to the at least        one base station;    -   the mobile station including means for storing rule information        relating to predetermined coding rules;    -   the mobile station also including means for retrieving said rule        information; and    -   the mobile station further including means for encoding, using        the retrieved rule information, signals to be transmitted to the        base station using the predetermined coding rules.

According to a sixth aspect of the invention there is provided a radiotelecommunications system comprising:

-   -   at least one base station; a plurality of mobile stations;    -   the at least one base station including means for transmitting        signals to and means for receiving signals from each mobile        station;    -   each mobile station including means for receiving signals from        and means for transmitting signals to the at least one base        station; each mobile station    -   including means for storing rule information relating to        predetermined coding rules;    -   each mobile station also including means for retrieving said        rule information; and    -   each mobile station further including means for encoding or        decoding, using the retrieved rule information, signals to be        transmitted to or signals received from a second mobile station        within the radio    -   telecommunications system which signals use the predetermined        coding rules.

According to a seventh aspect of the invention there is provided amethod of decoding signals sent by a radio telecommunications system,said system comprising at least one base station and at least one mobilestation, comprising:

-   -   storing, in the mobile station, rule information relating to        predetermined coding rules;    -   retrieving said rule information;    -   decoding, using the retrieved rule information, signals received        from the radio telecommunications system.

According to a eighth aspect of the invention there is provided a methodof encoding signals sent to a radio telecommunications system, saidsystem comprising at least one base station and at least one mobilestation, comprising: storing, in the mobile station, rule informationrelating to predetermined coding rules;

-   -   retrieving said rule information:    -   encoding, using the retrieved rule information, signals to be        transmitted to the radio telecommunications system.

According to a ninth aspect of the invention there is provided a methodof encoding or decoding signals sent from a first mobile station to asecond mobile station within a radio telecommunications system,comprising:

-   -   storing, in each mobile station, rule information relating to        predetermined coding rules;    -   retrieving said rule information;    -   encoding or decoding, using the retrieved rule information,        signals to be transmitted to or signals received from the second        mobile station, which signals use the predetermined coding        rules.

According to a tenth aspect of the invention there is provided a radiotelecommunications system for broadcasting encoded broadcast informationover a coverage area, comprising:

-   -   at least one mobile station;        the at least one base station including means for transmitting,        over the coverage area, generic broadcast information in an        unencoded format;    -   the at least one mobile station including means for receiving        said generic broadcast information at the least one base        station;        the mobile station including means for establishing a connection        between the mobile station and the base station, using the        generic broadcast information;    -   the base station including means for transmitting, over the        connection to the mobile station, rule information relating to        predetermined coding rules;    -   the mobile station also including means for storing rule        information;    -   the mobile station further including means for retrieving said        rule information;        the base station also including means for transmitting, over the        coverage area, non-generic broadcast information encoded using        the predetermined coding rules; and    -   wherein said mobile station further includes means for decoding,        using the retrieved rule information, the non-generic broadcast        information transmitted by the base station.

According to a eleventh aspect of the invention there is provided amethod of broadcasting encoded broadcast information over a coveragearea in a radio telecommunications system, said system comprising atleast one base station and at least one mobile station, comprising:

-   -   transmitting generic broadcast information in an unencoded        format over the coverage area:    -   receiving said generic broadcast information at said mobile        station;    -   said mobile station using the generic broadcast information to        establish a connection between the mobile station and the base        station transmitting, over the connection and from the base        station to the mobile station, rule information relating to        predetermined coding rules;    -   transmitting, from die base station, non-generic broadcast        information encoded using the predetermined coding rules; and    -   said mobile station using said rule information to decode said        non-generic broadcast information.

According to a twelfth aspect of the invention there is provided amethod of programming, by a radio telecommunications system a mobilestation over a connection, said system comprising at least one basestation, comprising:

-   -   establishing a connection between the mobile station and the at        least one base station;    -   the base station transmitting, over the connection, rule        information relating to predetermined coding rules:    -   programmig the mobile station with said rule information;        retrieving said rule information;    -   the mobile station encoding or decoding, using the retrieved        rule information, signals to be transmitted to or received from        the radio telecommunications system.

According to a thirteenth aspect of the invention there is provided amethod of programming, by a radio telecommunications system a mobilestation over a connection, said system comprising at least one basestation and at least one other mobile station, comprising:

-   -   establishing a connection between the mobile station and the at        least one base station;    -   the base station transmitting, over the connection, rule        information relating to predetermined coding rules:    -   programming the mobile station with said rule information;    -   retrieving said rule information;    -   the mobile station encoding or decoding, using the retrieved        rule information, signals to be transmitted to or received from        the at least one other mobile station.

According to another aspect of the invention there is provided a radiotelecommunications system comprising:

-   -   at least one base station;    -   at least one mobile station;    -   the at least one base station including means for transmitting        signals to and means for receiving signals fro5m the at least        one mobile station;    -   the at least one mobile station including means for receiving        signals from and means for transmitting signals to the at least        one base station;    -   the base station also including means for transmitting, to the        mobile station, rule information relating to predetermined        coding rules;    -   the mobile station also including means for storing and means        for retrieving said rule information; and    -   the mobile station further including means for decoding, using        the retrieved rule information, signals transmitted by the base        station using the predetermined coding rules.

According to yet another aspect of the invention there is provided aradio telecommunications system comprising:

-   -   at least one base station: at least one mobile station:    -   the at least one base station including means for transmitting        signals to and means for receiving signals from the at least one        mobile station:    -   the at least one mobile station including means for receiving        signals from and means for transmitting signals to the at least        one base station;    -   the base station also including means for transmitting, to the        mobile station, rule information relating to predetermined        coding rules;    -   the mobile station also including means for storing and means        for retrieving said rule information; and    -   the mobile station further including means for encoding, using        the retrieved rule information, signals to be transmitted to the        base station using the predetermined coding rules.

The invention provides methods and apparatus to enable the mobilestation to encode and/or decode messages, for example messages broadcastby the base station on a broadcast channel. The encoding and decoding isbased on a set of rules downloaded to die mobile station into an area ofapplication space or storage dedicated to this function. In thefollowing description, both the application space and rule informationloaded into the application space are referred to as the “code-book.

The rules relating to the encoding and decoding information may bedownloaded during registration with the radio telecommunications systemor during another type of communication or connection with the radiotelecommunications system. The rule information may be down-loaded tothe storing means over broadcast channel, or another control channel oralternatively over a dedicated communications channel. The ruleinformation may also be down-loaded to the storing means during adedicated communication period separate from the communication requitedto register the mobile station with the radio telecommunications system.Alternatively, the rules may be pre-loaded into the mobile station, forexample when the mobile station is configured for operation on a radiotelecommunications system by a particular operator.

The rule information may be updated as the mobile moves around the radiotelecommunications system (or PLMN, public land-mobile network) andenters a new area of the radio telecommunications system, for example asthe mobile moves between registration areas, or even cells within thenetwork. The rule information may also be updated during the course of adedicated communication between the mobile station and its serving basestation, for example in order to facilitate the change from a GSM callto a WCOMA UMTS call) or vice versa, or as the functionality of theradio telecommunications system is dynamically updated, for exampleduring peak or off-peak hours.

The rule information enables the mobile station to decode, amongst othersignals, broadcast information from the radio telecommunications system;the broadcast information may be partly encoded in accordance with thepredetermined decoding rules, and partly in unencoded format or codedusing the standard schemes supported by existing communicationsprorocols. The radio telecommunications system may be a digital radiotelecommunications system.

The summary of the invention does not necessarily disclose all thefeatures essential for defining the invention; the invention may residein a sub-combination of the disclosed features.

One advantage of the invention is that it provides a mechanism by whichbroadcast information may be compressed and thereby broadcast capacitycan be increased.

Another advantage of the invention is that it allows the broadcastinformation to be tailored to the specific operation of a given radiotelecommunications system and thereby minimises the overhead caused bybroadcast messages needed to fulfill generic needs of the protocolemployed by the system.

Yet another advantage of the inventions is that it alleviates theproblems of prior art cellular communication systems, and to optimisesUMTS systems for future deployment.

Yet another advantage of the invention is that it alleviates theproblems of prior art cellular communication systems, and to optimisesUMTS systems for future deployment.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention are described below, by way of exampleonly, and with reference to the following figures, in which:

FIG. 1 illustrates the general scheme of a personal mobile radio system;

FIG. 2 illustrates in outline a mobile station according to theinvention;

FIG. 3 illustrates an example of signals transmitted between a basestation and a mobile station to download rule information according toone embodiment of the invention;

FIG. 4 illustrates graphically a simplified example of a code-book andBOCH message according to the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description is of preferred embodiments only withoutlimitation to the combination of features necessary for putting theinvention into effect.

FIG. 1 illustrates the general scheme of a PLMN cellular mobiletelecommunications system 10. Mobile stations 2, 4 and 6 of FIG. 1 cancommunicate with a base station 8. Mobile stations 2, 4 and 6 couldequally well be mounted in vehicles. Each of the mobile stations shownin FIG. 1 can communicate via base station 8 with one or more othermobile stations.

Alternatively, the mobile devices may communicate with other users notpart of the PLMN, via other public telecommunications networks connectedto the cellular telecommunications system. If mobile stations 2, 4 and 6are capable of direct mode operation, then they may communicate directlywith one another or with other mobile devices, without the communicationlink passing through base station 8.

Portable mobile radios and their base stations comprise analogousarrangements to those shown in FIG. 1.

As described above. FIG. 1 illustrates the general scheme of a cellularmobile telecommunication system 10, called hereafter the mobiletelecommunications network or PLMN.

Immediately after being switched on or recovering coverage (i.e. uponentering an area of coverage from an area of no coverage), the mobilestation searches for a mobile telecommunications network. The mobilestation only needs to receive broadcast information containing theidentity of the mobile telecommunications network and informationregarding initial access to the mobile telecommunications network, forexample in order to register on the network.

Imagine that mobile station 2 enters the scenario of FIG. 1, which inthis embodiment represents a cellular mobile telecommunications systemand searches for the mobile telecommunications network. Once broadcastinformation, transmitted by the base station 8, is received by themobile station. The mobile station requests a connection to the basestation, which when granted allows the mobile station to reaister withthe mobile telecommunications network, e.g. using the GSM attachprocedure or registration procedure. During the connection establishedfor the registration procedure or any other initial access by the mobilestation, the network transmits, via the down-link established betweenthe base station and the mobile station, rule information in the form ofa code-book to the mobile station. This code-book is stored in aseparate area of the mobile station and is illustrated in more detail inFIG. 2.

The mobile station comprises a transmitter 22 and a receiver 28 coupledvia a switch 24 to antenna 26. The signals transmitted by the mobilestation are generated by the mobile station controller (or processor)20. Likewise, signals 29 received at the antenna 26 are also processedby the controller. The controller is also connected to a microphone 34,a data terminal 36, a speaker 40 via audio processor 38, display 42 anda keypad 44. Also connected to the controller is a ROM device 32 forstoring fixed, essential information used by the controller incommunicating with the network, such as the mobile stationidentification codes etc. Also connected to the controller is acode-book store 46, for example an area of RAM, flash RAM or NV RAM. Thecontroller determines whether the information received from the network,via the base station, is rule information, representative ofpredetermined coding rules, which should be stored in the code book.Once stored in the code-book store, the rule information can beretrieved and used by the controller to decode the data, or information,contained in signals received at the mobile station antenna. Likewise,the rule information can be used by the controller to encode data to betransmitted in signals transmitted by the mobile station antenna.

The rule information may be updated, for example when the mobile station25 moves between registration areas, or when the functionality of thenetwork system changes.

Thus the rule information stored in the code book enables data insignals transmitted to and from the mobile station to be encodedaccording to predetermined coding rules. Since the rule information issent to the mobile station during a connection with the network, thetype of coding rules employed may thus be flexible and changeddynamically.

The code-book technique can be extended to be used to “compress”point-to point signalling as well, if the rule information suppliedincludes a set of encoding rules. Either a general code-book (containingboth decoding rules and encoding rules) may be sent, for example atregistration, or a dedicated code-book (containing encoding rules to beused for the connection) is sent in the early phase of an establishedconnection.

The code-book of the invention is especially useful for allowingencoding o Associated control channels (ACCH). These channels may betransmitted in parallel with the user information transfer or arerealised by frame stealing within the user information transfer. In bothcases, the bandwidth is limited.

It will thus now be apparent to one skilled in the art that the codebook may be employed in a number of different situations, some of whichare described in more detail below.

In order to obtain initial access to a network, or PLMN, only a limitedamount of information is needed. Typically, it is sufficient to check ifaccess is allowable and the communication resource is likely to providea usable signalling link. This limited information is referred in thefollowing description as the “generic broadcast information”.

In a first example, the rule information is transmitted by the networkand stored in the code-book store may contain, amongst other things, thedecoding rules for further broadcast information which is not a part ofthe generic broadcast information. This allows compression of thebroadcast information to the minimum required for the operation of thegiven network. The code-book can be updated during any later access tothe network; however to minimise the need for updating, the code-bookmay maintain constant or identical decoding rules across a registrationarea or a full PLMN. If die decoding rules are kept constant within aregistration area, the use of the code-book will not generate the needfor additional access to the network, as the mobile would normally haveto access the network at change of registration area.

Once downloaded from the network, the mobile station utilises thereceived code-book to decode any further broadcast information. Thebroadcast information can, as described above, be considered to consistof two parts the “generic” broadcast information and the “non-generic”broadcast information. In addition this latter non-generic informationcan again be split into two parts, one part may be transmitted in such amanner as not to require the code-book to decode the information,although the information may never-the-less be encoded using encodingschemes or processes supported by the protocol running on the network.The other part of the information may require the code-book to decode orunderstand the information.

Registration and downloading of the rule information, or code-book, isillustrated in FIG. 3, using by way of example the GSM location updateprocedure. On receiving the BCCH signal the mobile requests a channelwith request 50. The network, via the base station, responds byassigning a channel with channel assignment 52, and begins transmittingthe code book rule information, in the code-book download 54. The mobileaccepts the code book information with code-book accept 56 and the restof the signals (60 to 72) are exchanged in the known manner. However,these signals may be encoded using the rule information, as describedabove, thereby enabling the messages exchanged (such as locationupdating 60 & 62, cipher mode 64 & 66, authentication 68 & 70 and TMSIallocation 72) to be compressed.

In a second example, a GSM network needs to broadcast information aboutneighboring cells in a UMTS network (or UMTS portion of the same PLMN).In a UMTS network the centre frequency of the W-CDMA carrier is placedon a 200 kHz raster and potentially uses variable duplex spacing. Thiswill, if generic encoding rules are used, require that for eachpotential neighbour the broadcast information is capable of indicatingany of approximately 300 potential carrier positions for up-linkcommunication and a similar number for down-link communications.However, in practice an operator will only have very few carriers, e.g.,an operator with an allocation of 2×20 MHz will only have 4–5 potentialcarrier up-link and down-link positions. If the code-book of theinvention is used, then the code-book transmitted to the mobile stationat, e.g. registration, can be used by the mobile to determine how octetN of message Y should be translated or decoded.

One example of such neighbor list encoding is illustrated therepresentation of the code books and messages of FIG. 4. The ruleinformation illustrated graphically by the look-up table 80 istransmitted by the GSM network to be stored in the code-book anddefines, amongst other things, the definitions of a number of UMTS WODMAcarriers (shown in FIG. 4 as carriers A to H). These definitions mayinclude either the up-link frequency or the down-link frequency orduplex spacing. The definitions may also include the mode, such asfrequency domain duplexing (FDD), time domain duplexing (TOD) etc., therelative timing and/or the code used (e.g. GMSK, codes rate).

Octet N of the message 82 illustrated represents a bit map, which inturn indicates the presence of carriers available as neighbors. Theexample octet, shown as 84, when decoded with the rule information fromthe code-book, indicates that carriers A,C,E,F and H are neighborcarriers.

The octet might also list the absolute frequency or absolute radiofrequency number corresponding to each bit. In the above example anyavailable UMTS neighbor frequency could be encoded in one octet on thebroadcast channel, with full flexibility in the spectrum allocation. Thebit mapping (that is, the look-up table for each bits which makes up theoctet) to the correct absolute frequency is provided through the ruleinformation stored in the code-book, which may, as described above, beprovided to the mobile station on a dedicated channel at some other timeduring the interaction.

A similar technique can be applied to indicate which neighbor cells tomeasure, for example when the mobile station is in dedicatedcommunication with the base station, such as when initiating orreceiving a call. This may be used in, for example, mobile assistedhandover.

The use of the invention in relation to dedicated connections can besplit into two main categories. In these examples of the invention, thecode-book is downloaded to the mobile station prior to the establishmentof the dedicated connection, e.g., at registration. The code-bookspecifies the encoding and decoding of messages or part of messagesexchanged between the network and the mobile station during thededicated connections.

A first dedicated connections example of the invention may be applied toa network (PLMN) consisting of both a GSM radio access portion and aUMTS radio access portion. The code-book is downloaded to the mobilestation, and specifies, in particular, that when messages contains someexplicit GSM ARFONs (Absolute Radio Frequency numbers), these should beinterpreted as given UMTS carriers (defined by mode (TDD/FFD),centre-frequency, duplex-spacing (for FDD) and possibly also bandwidthand chiprate). This use of the code-book thus allows reuse of GSMsignaling, e.g., to command mobile stations in connected mode to monitorUMTS carriers for neighbor measurement reporting. In addition, thecode-book can be used to compress the signaling channels and therebydecrease the overhead required for signaling. This process may beadapted and applied to the broadcast examples discussed previously.

In a second dedicated connections example of the invention, thecode-book is downloaded and/or updated during an established dedicatedconnection. This can be implemented in conjunction with the firstdedicated communication example described above, to update the code-bookstored in the mobile station, e.g. in cases where the network is beingreconfigured, or independently. Alternatively, this second dedicatedcommunication example may be used for time critical messages such as,e.g., assignment and handover messages, where too large a message sizewould cause segmentation and thereby introduce a transmission delay.Such messages will typically be defined to cope with all types ofconfiguration and modes of operation. By using a code-book, specifiedand downloaded to the mobile station, the time critical messages may bekept small because bits are only assigned to signal information relevantfor the actual configuration and mode of operation in the given cell,registration area, or PLMN. Additionally, and as above, the code-bookcan be used for compression of the signaling channels and therebydecrease the overhead required for signaling.

The code-book may also be used to specify error correcting codes used,e.g., on the physical layer or upper layers. For example, a code-bookwhich specifies types of error correcting codes (Convolutional.Reed-Solomon, Turbo-code etc., the rate (e.g., 172, /13, 2/3 etc), thegenerator polynominals, and tailbit), may be downloaded to the mobile.This example provides the means for flexible allocation of protectionlevel and may also be used to define broadcast channels.

1. A mobile station for communicating with a radio telecommunicationssystem, the mobile station comprising: means for communicating with theradio telecommunications system; means for receiving rule informationrelating to predetermined coding rules from the radio telecommunicationsystem over an air interface; means for storing said rule information;means for retrieving said rule information; means for decoding, usingthe retrieved rule information, signals received from the radiotelecommunications system, wherein the rule information enables themobile station to decode broadcast information from thetelecommunications system, the broadcast information being partlyencoded in accordance with the predetermined coding rules, and partly inunencoded format.
 2. A mobile station for communication over atelecommunications system, the mobile station comprising: means forcommunicating with the radio telecommunications system; means forreceiving rule information relating to predetermined coding rules fromthe telecommunication system over an air interface; means for storingand retrieving said rule information; means for encoding, using theretrieved rule information, signals to be transmitted to the radiotelecommunications system, wherein the rule information enables themobile station to encode information for the telecommunications system,the information being partly encoded in accordance with thepredetermined coding rules, and partly in unencoded format.
 3. A firstmobile station for communicating with second mobile station in atelecommunications system, the first mobile station comprising: meansfor receiving rule information relating to predetermined coding rulesfrom the telecommunication system over an air interface; means forstoring said rule information; means for communicating with the secondmobile station; means for retrieving said rule information; means forencoding or decoding, using the retrieved rule information, signals tobe transmitted to or signals received from the second mobile station,which signals use the predetermined coding rules, wherein thepredetermined coding rules enables the mobile station to encode ordecode information for the other mobile station, the information beingpartly encoded in accordance with the predetermined coding rules, andpartly in unencoded format.
 4. A mobile station in accordance with claim1, 2 or 3, wherein the rule information is down-loaded to the storingmeans during registration of the mobile station with thetelecommunications system.
 5. A mobile station in accordance with claim1, 2 or 3, wherein the rule information is down-loaded to the storingmeans over a dedicated communications channel.
 6. A mobile station inaccordance with claim 1, 2 or 3, wherein the rule information isdown-loaded to the storing means during a dedicated communication periodseparate from the communication required to register the mobile stationwith the telecommunications system.
 7. A mobile station in accordancewith claim 1, 2 or 3, wherein the rule information is down-loaded to thestoring means as pre-loaded information, prior to registration of themobile station with the telecommunications system.
 8. A mobile stationin accordance with claim 1, wherein the rule information is up-datedeach time that the mobile station enters a new area of the radiotelecommunications system.
 9. A mobile station in accordance with claim1, wherein the rule information is up-dated each time that the mobilestation enters a new registration area of the radio telecommunicationssystem.
 10. A mobile station in accordance with claim 1, wherein therule information is up-dated each time that the mobile station enters anew cell of the radio telecommunications system.
 11. A mobile station inaccordance with claim 1, wherein the rule information enables the mobilestation to decode broadcast information from the telecommunicationssystem.
 12. A mobile station in accordance with claim 1, where the radiotelecommunications system is a digital radio telecommunications system.13. A radio telecommunications system comprising; at least one basestation; at least one mobile station; the at least one base stationincluding means for transmitting signals to and means for receivingsignals from the at least one mobile station; the at least one mobilestation including means for receiving signals from and means fortransmitting signals to the at least one base station; the mobilestation comprising means for receiving rule information relating topredetermined coding rules from the radio telecommunication system overan air interface; the mobile station also including means for storingsaid rule information; the mobile station also including means forretrieving said rule information; and the mobile station furtherincluding means for decoding, using the retrieved rule information,signals transmitted by the base station using the predetermined codingrules, wherein the rule information enables mobile station to decode thesignals from the telecommunications system, the signals being partlyencoded in accordance with the predetermined coding rules, and partly inunencoded format.
 14. A radio telecommunications system comprising: atleast one base station; at least one mobile station; the at least onebase station including means for transmitting signals to and means forreceiving signals from the at least one mobile station; the at least onemobile station including means for receiving signals from and means fortransmitting signals to the at toast one base station; the mobilestation comprising means for receiving rule information relating topredetermined coding rules from the radio telecommunication system overan air interface; the mobile station also including means for storingsaid rule information; the mobile station also including means forretrieving said rule information; and the mobile station furtherincluding means for encoding, using the retrieved rule information,signals to be transmitted to the base station using the predeterminedcoding rules, wherein the rule information enables the mobile station toencode the signals for the telecommunications system, the signals beingpartly encoded in accordance with the predetermined coding rules, andpartly in unencoded format.
 15. A radio telecommunications systemcomprising: at least one base station; a plurality of mobile stations;the at least one base station including means for transmitting signalsto and means for receiving signals from each mobile station; each mobilestation including means for receiving signals from and means fortransmitting signals to the at least one base station; each mobilestation comprising means for receiving rule information relating topredetermined coding rules from the radio telecommunication system overan air interface; each mobile station also including means for storingsaid rule information; each mobile station also including means forretrieving said rule information; and each mobile station furtherincluding means for encoding or decoding, using the retrieved ruleinformation, signals to be transmitted to or signals received from asecond mobile station within the radio telecommunications system whichsignals use the predetermined coding rules, wherein the rule informationenables the mobile station to encode or decode the signals for the othermobile station, the signals being partly encoded or decoded inaccordance with the predetermined coding rules, and partly in unencodedformat.
 16. A radio telecommunications system in accordance with claim13, 14 or 15, wherein the rule information is down-loaded to the storingmeans of the mobile station during registration of the mobile stationwith the telecommunications system.
 17. A radio telecommunicationssystem in accordance with claim 13, 14 or 15, wherein the ruleinformation is down-loaded to the storing of the mobile station meansover a dedicated communications channel.
 18. A radio telecommunicationssystem in accordance with claim 13, 14 or 15, wherein the ruleinformation is down-loaded to the storing of the mobile station meansduring a dedicated communication period separate from the communicationrequired to register the mobile station with the telecommunicationssystem.
 19. A radio telecommunications system in accordance with claim13, 14 or 15, wherein the rule information is downloaded to the storingof the mobile station means as pre-loaded information, prior toregistration of the mobile station with the telecommunications system.20. A radio telecommunications system in accordance with claim 13,wherein the rule information is up-dated each time that the mobilestation enters a now area of the radio telecommunications system.
 21. Aradio telecommunications system in accordance with claim 13, wherein therule information is up-dated each time that the mobile station enters anew registration area of the radio telecommunications system.
 22. Aradio telecommunications system in accordance with claim 13, wherein therule information is up-dated each time that the mobile station enters anew cell of the radio telecommunications system.
 23. A radiotelecommunications system in accordance with claim 13, wherein the ruleinformation enables the mobile station to decode broadcast informationfrom the telecommunications system.
 24. A radio telecommunicationssystem in accordance with claim 13, where the radio telecommunicationssystem is a digital radio telecommunications system.
 25. A method ofdecoding signals sent by a radio telecommunications system said systemcomprising at least one base station and at least one mobile station,comprising: receiving, by the mobile station, rule information relatingto predetermined coding rules from the radio telecommunication systemover an air interface; storing, in the mobile station, said ruleinformation; retrieving said rule information; decoding, using theretrieved rule information, signals received from the radiotelecommunications system, the signals being partly encoded inaccordance with the predetermined coding rules, and partly in unencodedformat.
 26. A method of encoding signals sent to a radiotelecommunications system, said system comprising at least one basestation and at least one mobile station, comprising: receiving, by themobile station, rule information relating to predetermined coding rulesfrom the radio telecommunication system over an air interface; storing,in the mobile station, said rule information; retrieving said ruleinformation; encoding, using the retrieved rule information, signals tobe transmitted to the radio telecommunications system, the signals beingpartly encoded in accordance with the predetermined coding rules, andpartly in unencoded format.
 27. A method of encoding or decoding signalssent from a first mobile station to a second mobile station within aradio telecommunications system, comprising: receiving, by each mobilestation, rule information relating to predetermined coding rules fromthe radio telecommunication system over an air interface; storing, ineach mobile station, said rule information; retrieving said ruleinformation; encoding or decoding, using the retrieved rule information,signals to be transmitted to or signals received from the second mobilestation, which signals use the predetermined coding rules, the signalsbeing partly encoded in accordance with the predetermined coding rules,and partly in unencoded format.
 28. A method in accordance with claim25, 26 or 27, comprising down-loading the rule information to thestoring means during registration of the mobile station with thetelecommunications system.
 29. A method in accordance with claim 25, 26or 27, comprising down-loading the rule information to the storing meansover a dedicated communications channel.
 30. A method in accordance withclaim 25, 26 or 27, comprising down-loading the rule information to thestoring means during a dedicated communication period separate from thecommunication required to register the mobile station with thetelecommunications system.
 31. A method in accordance with claim 25, 26or 27, comprising down-loading the rule information to the storing meansas pre-loaded information, prior to registration of the mobile stationwith the telecommunications system.
 32. A method in accordance withclaim 25, comprising up-dating the rule information each time that themobile station enters a new area of the radio telecommunications system.33. A method in accordance with claim 25, comprising up-dating the ruleinformation each time that the mobile station enters a new registrationarea of the radio telecommunications system.
 34. A method in accordancewith claim 25, comprising up-dating the rule information each time thatthe mobile station enters a new cell of the radio telecommunicationssystem.
 35. A method in accordance with claim 25, comprising enablingthe mobile station to decode, using the rule information, broadcastinformation from the telecommunications system.
 36. A method inaccordance with claim 26, where the radio telecommunications system is adigital radio telecommunications system.
 37. A radio telecommunicationssystem for broadcasting encoded broadcast information over a coveragearea, comprising: at least one mobile station; the at least one basestation including means for transmitting, over the coverage area,generic broadcast information in an unencoded format; the at least onemobile station including means for receiving said generic broadcastinformation at the least one base station; the mobile station includingmeans for establishing a connection between the mobile station and thebase station, using the generic broadcast information; the base stationincluding means for transmitting, over the connection to the mobilestation, rule information relating to predetermined coding rules; themobile station also including means for receiving said rule informationfrom the base station over an air interface; the mobile station alsoincluding means for storing rule information; the mobile station furtherincluding means for retrieving said rule information; the base stationalso including means for transmitting, over the coverage area,non-generic broadcast information encoded using the predetermined codingrules; and wherein said mobile station further includes means fordecoding, using the retrieved rule information, the non-genericbroadcast information transmitted by the base station, the non-genericbroadcast information is partly encoded in accordance with thepredetermined coding rules, and partly in unencoded format.
 38. A radiotelecommunications system in accordance with claim 37, where, in thealternative to the base station including means for transmitting, overthe connection to the mobile station, rule information relating topredetermined coding rules, the rule information is down-loaded to thestoring means of the mobile station means as pre-loaded information. 39.A radio telecommunications system in accordance with claim 37, whereinthe rule information is up-dated each time that the mobile stationenters a new area of the radio telecommunications system.
 40. A radiotelecommunications system in accordance with claims 37, wherein the ruleinformation is up-dated each time that the mobile station enters a newregistration area of the radio telecommunications system.
 41. A radiotelecommunications system in accordance with claims 37, wherein the ruleinformation is up-dated each time that the mobile station enters a newcell of the radio telecommunications system.
 42. A radiotelecommunications system in accordance with claim 37, where the radiotelecommunications system is a digital radio telecommunications system.43. A method of broadcasting encoded broadcast information over acoverage area in a radio telecommunications system, said systemcomprising at least one base station and at least one mobile station,comprising: transmitting generic broadcast information in an unencodedformat over the coverage area; receiving said generic broadcastinformation at said mobile station; said mobile station using thegeneric broadcast information to establish a connection between themobile station and the base station; transmitting, over the connectionand from the base station to the mobile station, rule informationrelating to predetermined coding rules; transmitting, from the bassstation, non-generic broadcast information encoded using thepredetermined coding rules; and the mobile station receiving said ruleinformation from the base station over an air interface; said mobilestation using said rule information to decode said non-generic broadcastinformation, the non-generic broadcast information is partly encoded inaccordance with the predetermined coding rules, and partly in unencodedformat.
 44. A method in accordance with claim 43, comprising, in thealternative to the base station transmitting, over the connection to themobile station, rule information relating to predetermined coding rules,the rule information is down-loaded to the storing means of the mobilestation means as pre-loaded information.
 45. A method in accordance withclaim 43, comprising updating the rule information each time that themobile station enters a new area of the radio telecommunications system.46. A method in accordance with claims 43, comprising updating the ruleinformation each time that the mobile station enters a new registrationarea of the radio telecommunications system.
 47. A method in accordancewith claims 43, comprising updating the rule information each time thatthe mobile station enters a new cell of the radio telecommunicationssystem.
 48. A method in accordance with claims 43, comprisingtransmitting the non-generic broadcast information in partly encoded inaccordance with the predetermined decoding rules, and partly inunencoded format.
 49. A method in accordance with claim 43, where theradio telecommunications system is a digital radio telecommunicationssystem.
 50. A method of programming, by a radio telecommunicationssystem a mobile station over a connection, said system comprising atleast one base station, comprising: establishing a connection betweenthe mobile station and the at least one base station; the base stationtransmitting, over the connection, rule information relating topredetermined coding rules; the mobile station receiving said ruleinformation from the base station over an air interface; programming themobile station with said rule information; retrieving said ruleinformation; the mobile station encoding or decoding, using theretrieved rule information, signals to be transmitted to or receivedfrom the radio telecommunications system, the signals being partlyencoded in accordance with the predetermined coding rules, and partly inunencoded format.
 51. A method of programming, by a radiotelecommunications system, a mobile station over a connection, saidsystem comprising at least one base station and at least one othermobile station, comprising: establishing a connection between the mobilestation and the at least one base station: the base stationtransmitting, over the connection, rule information relating topredetermined coding rules; the mobile station receiving said ruleInformation from the base station over an air interface; programming themobile station with said rule information; retrieving said ruleinformation; the mobile station encoding or decoding, using theretrieved rule information, signals to be transmitted to or receivedfrom the at least one other mobile station, the signals being partlyencoded in accordance with the predetermined coding rules, and partly inunencoded format.
 52. A method in accordance with claims 50 or 51,comprising updating the rule information each time that the mobilestation enters a new area of the radio telecommunications system.
 53. Amethod in accordance with claims 50 or 51, comprising updating the ruleinformation each time that the mobile station enters a new registrationarea of the radio telecommunications system.
 54. A method in accordancewith claims 50 or 51, comprising updating the rule information each timethat the mobile station enters a new cell of the radiotelecommunications system.
 55. A method in accordance with claims 50 or51, comprising enabling the mobile station to decode, using the ruleinformation, broadcast information from the telecommunications system.56. A method in accordance with claims 50 or 51, where the radiotelecommunications system is a digital radio telecommunications system.